Energy discharge device



March 25, 1969 J, G. ROHA' 3,434,383

ENERGY DI S CHARGE DEVICE Filed April 17, 1968 sheet of 4 t -H 99 "si FlW \\g INVENTOR Juhu G Rom-hn.

BY I my ATTORNEYS March 25, 1969 J. G. ROCHA 3,434,383

ENERGY EISCHARGE DEVICE Filed April 17, 1968 sheet el g E: @j QF v il?3"- N Sk N v f. if',

Eig- 21- x (9) j @Z113 .l L L0 %/r\ ce s 5 m @m J. G. ROCHA ENERGYDISCHARGE DEVICE March 25, 1969 Filed April 17. 1968 Sheet Ill! ' @l fHIIIIIIIIIIF www@ INVENTOR .In-hn E Rnhtl.

BY I pw March 25, 1969 J. G. ROCHA 3,434,383

ENERGY D I S CHARGE DEVICE Filed April' 17, 196s Y sheet 4 of 4 36 fr-I4Eigpaj-E- 2e 1 NVENTOR @MW Juhu E Runm ATTORNEYS States Patent Ofce3,434,383 ENERGY DISCHARGE DEVICE John G. Rocha, Westfield, Mass.,assignor to the United States of America as represented by the Secretaryof the Army Filed Apr. 17, 1968, Ser. No. 722,045 Int. Cl. F41f 5/02,19/00 U.S. Cl. 89-42 9 Claims ABSTRACT OF THE DISCLOSURE The inventiondescribed herein may be manufactured, used, and licensed by or for theGovernment for governmental purposes without the payment to me of anyroyalty thereon.

With the use of helicopters as -weapon carriers, the recoil forcesproduced by cartridge discharge have become a major problem becausehelicopters are sensitive to outside forces, as to holding theirpositions in space, and therefore provide an unstable platform formounting guns which produce adverse forces of any sizable magnitude whenred.

It is, therefore, a principal object of this invention to provide forautomatic guns having a mount and a recoil assembly slidingly mountedthereon for reciprocation responsive to recoil forces an energydischarge device operationally disposed between the mount and the recoilassembly for absorbing the energy transferred thereto with the dischargeof a cartridge in the barrel component thereof and then discharging theabsorbed energy at the end of the recoil displacement so that it is nottransferred back to the recoil assembly.

It is a further object of this invention to provide such an energydischarge device which includes a torsion spring arranged to be woundduring recoil displacement of the recoil assembly so as to absorb theenergy transferred thereto by cartridge discharge and then freeing thetorsion spring at the end of the recoil stroke to release the storedenergy therein. Y

Other objects and advantages of the invention will be apparent from thefollowing specification and accompanying drawings which are for thepurpose of illustration only and in which:

FIG. 1 is a top view of an automatic gun -with the recoil assemblydisposed adjacent battery position on the mount thereof;

FIG. 2 is an enlarged View taken along line 2 2 of FIG. 1;

FIG. 3 is a view taken along line 3 3 of FIG. 2;

FIG. 4 is a vieW taken along line 4 4 of FIG. 2;

FIG. 5 is a View similar to FIG. 2 but showing the relationship of theparts of one of the two energy discharge devices in the gun when therecoil assembly is adjacent the recoil position;

FIG. 6 is a fragmentary view similar to FIG. 5 but showing therelationships of the parts of the illustrated energy discharge devicewhen the recoil assembly is adjacent recoil position, the piston isclear of the rail device and the torsion bar is deenergized;

FIG. 7 is a view similar to FIG. 6 but showing the re- 3,434,383Patented Mar. 25, 1969 lationship of the piston relative to the raildevice as the recoil assembly is spring pressed towards batteryposition;

FIG. 8 is a view taken along line 8 8 of FIG. 6;

FIG. 9 is a view taken along line 9 9 of FIG. 7; and

FIG. 10 is a view taken along line 10 10` of FIG. 5.

Shown in the figures is an automatic gun 12 comprising a mount 14 and arecoil assembly 16 mounted thereon for sliding displacement between arearward recoil position and a forward battery position. Recoil assembly16 is driven to the recoil position responsive to discharge energyproduced when a cartridge is tired in barrel 18 which is a component ofthe recoil assembly. The greater portion of the discharge energyimparted to recoil assembly 16 is absorbed and then discharged withouttransfer back thereto by a pair of energy discharge devices 20operationally disposed between the mount and the recoil assembly.Suflicient energy is retained by energy discharge devices 20 ashereinafter described, to return recoil assembly 16 to its batteryposition.

Energy discharge devices 20 are mounted on opposite sides of gun 12 andeach includes a torsion bar 22 housed within a channel member 23 formedon one side of mount 14. Torsion bars 22 are fixed at their front endsto the front ends of the respective channel members 23 so as to beparallel to the axis of movement of recoil assembly 16. Each torsion bar22 is rectangular in cross section and is permanently twisted at therear portion to form a helical section 24 in which the rear end isdisposed at an angle respective to forward straight section 26 of thetorsion bar.

An arm 28, terminated by a cylindrical driver 30, extends laterally fromeach side of recoil assembly 16 into the respective channel member 23.Each of the drivers 30 is provided with a bore 32 that receives therelated one of the torsion bars 22, so that the drivers traveltherealong during reciprocation of recoil assembly 16. Slidingly mountedon each of the torsion bars 22 rearwardly of drivers 30 is la piston 34which is displaceable thereby along helical sections 24 during recoiltravel of recoil assembly 16. Each of the pistons 34 is of ellipticalconfiguration with a pair of acute tips 36 and each is provided with aconcentric bore 38 having a diameter somewhat smaller than the widestside of torsion bar 22. Diametrically opposed slots 39 are formed inbore 38 to receive the opposite edges of the associated torsion bar 22,as shown in FIG. 4. Each slot 39 forms a driving surface 40 and aIworking surface 41. Each driving surface 40 is slidingly contactablewith one side of torsion bar 22 when piston 34 is moved rearwardly alonghelical section 24 and working surface 41 of the same slot 39 iscontactable with the opposite side of the torsion bar when the piston ismoved forwardly along the helical section. Driving surfaces 40 contactthe associated torsion bar 22 on opposite sides thereof, as shown inFIG. 4, and working surfaces 41 are similarly contactable with thetorsion bar, as shown in FIG. 9. Driving surfaces 50 and working surface41 are spaced according to the helix of helical sections 24 and thethickness of pistons 34 to prevent interference therewith duringrelative displacement.

Thus, when pistons 34 are held against rotation, as hereinafterdescribed, torsion bars 22 are twisted when the pistons are movedrearwardly along helical sections 24 by sliding contact of drivingsurfaces 40 therewith. Pistons 34 are each held against rotation ashelical sections 24 pass therethrough through the cooperation of tips 36on each of the pistons with an associated rail device 42 formed in eachof the channel members 23. Each of the rail devices 42 includes an upperrail 44 and a lower rail 46. Upper rails 44 are each provided with asliding surface 47 formed on the underside thereof and lower rails 96are each provided with a sliding surface 49 formed on the top thereofand such sliding surfaces are each slidingly contactable by one of thetips 36.

Tips 36 and sliding surfaces 47 and 49 are so related that the pressureapplied Iby the tips thereto when pistons 34 are moved rearwardly alonghelical sections 24 are along vertical axes of gun 12. Upper rails 44and lower rails 46 each include a fixed section 48 and a displaceablesection 50 located forwardly thereof and contiguous thereto,Displaceable sections 50 are slidingly mounted in channel members 23 byT-slot means 51 for lateral displacement between normal positions inalignment with the related fixed sections 48 and retracted positionsclear of interference with tips 36 during rotation of pistons 34 byhelical sections 24 when moved forwardly therealong. Displaceablesections 50 are spring biased to their normal positions.

Fixed sections 48 are each provided with a rear end 52 which is locatedso that when recoil assembly 16 is adjacent its recoil position tips 36are clear of rail devices 42 whereby, pistons 34 are free to be rotatedby torsion bars 2 for discharge of the energy stored therein duringrecoil travel of recoil assembly 16. A coiled compression spring 54encircles each torsion bar 22 between a head 56 fixed to the rear endthereof and the related piston 34 which is pressed thereby against therelated driver 30 for biasing recoil assembly 16 to its batteryposition. Springs 54 are designed to store only sufficient energy topositively return recoil assembly 16 to battery position so that aminimum of excess energy is transferred by impact from recoil assembly16 to mount 14 when stopped at the battery position.

OPERATION In gun 12, as illustrated in the figures, helical section 24of the right one of the energy discharge devices 20 (looking forwardlyfrom the rear end of the gun), which is the bottom one in FIG. 1, twistsforwardly in a clockwise direction. The left one of the helical sections24 twists oppositely in the counterclockwise direction. As shown inFIGS. 2 and 4, when recoil assembly 16 is adjacent battery position,pistons 34 are located slightly forward of the related helical sections24 with one of the tips 36 of each of the pistons in contact withsliding surface 47 0f the related upper rail 44 and the other tip incontact with sliding surface 49 of the related lower rail 46, so thatthe pistons are held against rotation when moved rearwardly along theassociated helical section.

When a cartridge is fired in barrel 18, the discharge force drivesrecoil assembly 16 rearwardly on mount 14 with drivers 30 moving pistons34 along the related helical sections 24. As pistons 34 are held againstrotation through the sliding contacts of tips 36 thereon with theassociated upper rails 44 and lower rails 46, the rearward travel of thepistons along helical sections 24 causes torsion bars 22 to be twistedand thereby absorb energy irnparted to recoil assembly 16 by cartridgedischarge. Some of the energy is transformed to heat through thefriction created Iby the displacement of driving surfaces 40 alonghelical sections 24 and of tips 36 along rail devices 42 and suicientenergy is absorbed by springs 54 to return recoil assembly 16 to batteryposition. The remaining greater proportion of the discharge energy isabsorbed by torsion bars 22 and this is discharged when recoil assembly16 is adjacent recoil position and tips 36 are clear of rail device 42so that torsion bars 22 are free to spin back to normal positions andthereby release the stored energy therein. Helical sections 24 aretwisted in opposite directions so that the adverse forces created bytorsion bars 22 and pistons 34 thereon spinning back to normal positionswill be balanced out.

When torsion bars 22 are relaxed, pistons 34 are rotated so that tips 36thereon 4are inwardly of upper rails 44 and lower rails 46, as shown forthe left one of the energy discharge devices 20 in FIG. 8. With theenergy in torsion bars 22 discharged, the stored energy in springs 54drive recoil assembly 16, through pistons 34, forwardly to batteryposition. The forward movement of pistons 34 along helical sections 24cause the pistons to be rotated against the inner sides of upper rails44 and lower rails 46 through the sliding contacts of working surfaces41 with helical sections 24, as shown for the left one of the energydischarge devices 20 in FIG. 9, to cammingly ap ply lateral pressureagainst displaceable sections 50 of the ra-ils for actuation thereof tothe retracted positions. Thus, tips 36 are free to be swung past theassociated rail devices 42 to their normal positions, one on each piston34 being under the associated upper rail 44 and the other being over theassociated lower rail 46. When tips 36 are in their normal positions,displaceable sections 50 are free to spring back to their normalpositions, whereby energy discharge devices 20 are in operatingcondition ready for the next discharge of a cartridge in barrel 18.

I claim:

1. In a gun having a mount and a recoil assembly slidingly mountedthereon for displacement from a lbattery to a recoil position responsiveto energy produced by discharge of a cartridge in the recoil assembly,an energy discharge device including a torsion spring, a rail device onthe mount, and a piston disposed on said torsion spring for displacementby the recoil assembly when traveling to the recoil position and forcooperation with said rail device and said torsion spring to translaterecoil displacement of the recoil assembly to twisting displacement ofsaid torsion spring for absorbing the energy imparted to the recoilassembly by cartridge discharge and discharging the energy when therecoil assembly reaches recoil position so that none remains in saidtorsion spring to be returned to the recoil assembly.

2. The energy discharge device as defined in claim 1 and including incombination with said torsion spring a compression spring operationallydisposed between the mount and recoil assembly for absorbing sufiicientenergy from the cartridge discharge during travel of the recoil assemblyto recoil position to return the recoil assembly to battery position.

3. The energy discharge device as defined in claim 1 wherein saidtorsion spring is of bar type with a rectangular cross-.section andincludes a helical section formed thereon, and said piston includes abore with diametrically opposed slots therein for receiving said torsionspring so as to be displaceable along said helical section and a drivingsurface formed by each of said slots, said driving surfaces arranged to`be slidingly contactable with opposite sides of said torsion spring atsaid helical section for converting non-rotating displacement of saidpiston by the recoil assembly to a twisting displacement of said torsionspring for absorbing the energy imparted by cartridge discharge to therecoil assembly.

4. The energy discharge device as defined in claim 3 wherein said raildevice includes an upper rail and a lower rail, and said piston is ofelliptical configuration with a pair of acute tips, said tips beingarranged for sliding contact with sliding surfaces of said upper andlower rails to prevent rotation of said piston when displaced along saidhelical section.

5. The energy discharge device as defined in claim 4 wherein said upperand lower rails and said torsion spring are each disposed parallel tothe travel of the recoil assembly, and wherein said upper and lowerrails are each terminated by an end located so that said tips are clearof said rail device when the recoil assembly is in recoil position topermit free rotation of said torsion spring in one direction fordischarge of the energy absorbed thereby.

6. The energy discharge device as defined in claim 5 wherein each ofsaid slots also forms a working surface contactable with said helicalsection along a side opposite that contacted by said driving surface ofsaid slot for rotating said piston in a direction opposite said onedirection when free of said rail device and said recoil assembly movesto battery position.

7. The energy discharge device as defined in claim 5 wherein each ofsaid upper and lower rails is provided with a displaceable sectionarranged to Ibe actuated from its normal position by the associated oneof said tips to permit rotational passage thereof past the associatedone of said rails when said piston is rotated by sliding contact of saidworking surfaces with said helical section during displacement of therecoil assembly to battery position, and said displaceable sections arespring pressed back to normal positions after said tips are pastthereby.

8. The energy discharge device as defined in claim 7 wherein said tipsand said upper and lower rails are so disposed in cooperation that thepressure applied by said tips thereto when said torsion spring istwisted by said piston is along Vertical axes of the gun, and whereinsaid References Cited UNITED STATES PATENTS 2,491,539 12/1949 Windham.

BENJAMIN A. BORCHELT, Primary Examiner. STEPHEN C. BENTLEY, AssistantExaminer.

